main()
{
    int a, i, m;
    printf ("There are following perfect numbers smaller than 1000:\n");
    for(a=1; a<1000; a++)
    {
        for (m=0,i=1; i<=a/2; i++)
         if(! (a%i)) m+=i;
        if (m==a)
         printf(" %d", a);
    }
}